Client|UI: Added ProgressWidget

Work in progress... (pun not intended)
Client|UI|ProgressWidget|Default Style: Basic implementation done

The ProgressWidget geometry is generated based on the old busyvisual
code.

The Default Style now contains colors for the progress widget, and
the wheel/gear images were copied into the pack.

LabelWidget can now be given a custom color that is multiplied into
the label image.